Here's why:
* Semicolons act like strong commas. They separate two independent clauses that are closely related.
* Independent clauses can stand alone as complete sentences. They have a subject and a verb and express a complete thought.
Example:
* *The sky was blue; the sun was shining.*
In this example, both "The sky was blue" and "the sun was shining" are complete sentences, but they are closely related and the semicolon helps to join them together.
When to capitalize:
You would capitalize the first word after a semicolon if the second clause is a complete sentence that could stand on its own.
Example:
* *The sky was blue; however, the air was chilly.*
Here, "however, the air was chilly" is a complete sentence that could stand alone.
Remember: It's always a good idea to check the context of the sentence and consider the intended meaning when deciding whether or not to capitalize after a semicolon.